Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antibiotics may not be enough to stop recurrent gastric lymphoma caused by Helicobacter pylori

26.08.2005


Research led by Dr. Anne Mueller at Stanford University School of Medicine demonstrates that successful eradication of Helicobacter may not prevent future aggressive gastric lymphoma since resting B cells are left behind. The paper by Mueller et al., "The role of antigenic drive and tumor-infiltrating accessory cells in the pathogenesis of Helicobacter-induced MALT lymphoma," appears in the September issue of The American Journal of Pathology.

Helicobacter pylori, a spiral bacterium of the stomach, infects more than half of the world’s population. It is now widely accepted that, aside from gastritis and ulcers, H. pylori is also a causative agent of gastric lymphoma, specifically gastric B cell lymphoma of mucosa-associated lymphoid tissue (MALT). While antibiotic treatment eradicates the bacteria and promotes tumor regression, the effects of re-infection on disease are more severe.

To address the effects of re-infection and the role of immune cells in disease progression, Dr. Mueller’s group used a mouse model of Helicobacter-induced MALT lymphoma that employs H. felis to mimic human disease in the mouse. Mice were infected with H. felis and maintained for 18 months before being assigned to one of three treatment groups: 1) no treatment (primarily infected), 2) antibiotic therapy to eradicate bacteria, or 3) antibiotic therapy followed by re-infection.



As expected, low-grade MALT lymphoma occurred in 35% of all infected animals. However, frank MALT lymphoma was more prevalent in re-infected animals (44%) than in primarily infected animals (25%). Transcription profiling identified B cell markers in mice that had been infected at any point in time, even after successful antibiotic treatment, suggesting that resting B cells remain in the gastric mucosa.

Lymphoid aggregates of re-infected animals also contained more proliferating cells than those of primarily infected or antibiotic-treated animals (46% vs. 23.2% or 4.8%, respectively). Closer inspection of the lymphoid aggregates revealed that the tumors were indeed derived from B cells and the main antigen-presenting cells were follicular dendritic cells. Finally, follicular dendritic cell numbers were highest in the tumors of re-infected animals followed by primarily infected and then antibiotic-treated animals, thus correlating with severity of gastric lymphoma.

Because it is the follicular dendritic cells that present antigen to T cells that in turn activate B cell proliferation, follicular dendritic cells appear to be better indicators of tumor behavior than B cells. Thus, follicular dendritic cells represent an untapped target in the fight against recurrent gastric lymphoma.

The significance of the described work is that gastric lymphoma progresses more rapidly upon secondary infection. Because resting B cells are left behind following antibiotic treatment, re-infection by H. pylori promotes the existing B cells to progress quickly into tumors. Therefore, it is important that treated patients be carefully monitored for H. pylori re-infection.

Audra Cox | EurekAlert!
Further information:
http://www.asip.org

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>